The state forestry agency in Mississippi used to operate a series of 
look out towers that were used for spotting forest fires during fire 
season, and at other times as needed.

Some of these towers also had houses adjoining them where the district 
tower supervisor lived.

The CB regulations of the 1960s said that the tip of the antenna must 
be no more than 20 feet above the roof of the tallest structure on the 
property.

You know where this is going.

The supervisor of the tower near where I grew up installed a CB 
antenna known as a Scanner, just above the roof of the fire tower. 
This placed the bottom of the antenna at about 180 feet above ground, 
not counting the elevation of the hill where the tower was located.

This setup was absolutely legal, and needless to say, it performed 
very well.

The Scanner was made by Antenna Specialists. It was 3 vertical 
dipoles, spaced 120 degrees apart. The directional pattern was 
controlled by switching the driven element among the 3 dipoles. This 
was accomplished by way of a 3 position switch that controlled a set 
of relays that were connected to a set of tuned phasing lines, which 
ran from the relay to each dipole. Later models also added a fourth 
switch position which made the antenna non-directional.

The performance of this antenna was similar to that of a 3 element 
beam, and you did not need a rotator. My brother and I had one at 70 
feet, which was slightly more than 20 feet above our house, and worked 
the world with it.

The fire tower guy chose this antenna so that he could have 
directivity, and because he could achieve a more stable mounting 
arrangement atop the tower.

My brother and I lost our antenna when a storm blew down our tower. I 
had just gotten my General license, so I salvaged one of the dipoles, 
and used it on 10 meters for quite some time.

I think parts of that dipole are still in my storage building.


Mike Duke, K5XU
American Council of Blind Radio Amateurs